Three images showing the evolution of teaching about the stethoscope. The first is Basil Hood at the bedside in 1906. The second is Karel Frederic Wenckebach demonstrating a boy’s heartbeat to a medical class: students listen through stethoscopes connected to a machine. (circa 1925) In the third, the class dispenses with the live boy, and listens to the first electric heart sound distribution system manufactured by Western Electric (circa 1929.) Images via The Wellcome Trust.
